阅读说明：本技术 乙烯/α-烯烃共聚物及其制备方法 (Ethylene/alpha-olefin copolymer and process for producing the same ) 是由 全晸浩 郑丞桓 孔镇衫 郭来根 李忠勳 李银精 周炫珍 朴仁成 朴想恩 于 2019-05-03 设计创作，主要内容包括：本发明提供了一种乙烯/α-烯烃共聚物及其制备方法,所述乙烯/α-烯烃共聚物具有窄的分子量分布以及低的密度和超低分子量,并且具有最少数目的不饱和官能团,特别是在不饱和官能团当中低含量的亚乙烯基,由此显示优异的物理性质。(The present invention provides an ethylene/alpha-olefin copolymer having a narrow molecular weight distribution and a low density and an ultra-low molecular weight, and having a minimum number of unsaturated functional groups, particularly a low content of vinylidene groups among the unsaturated functional groups, thereby exhibiting excellent physical properties, and a method for preparing the same.)

1. An ethylene/α -olefin copolymer satisfying the following conditions i) to iv):

i) viscosity: from 6,000cP to 40,000cP when measured at a temperature of 180 ℃,

ii) Molecular Weight Distribution (MWD): 1.5 to 3.0, in a molar ratio,

iii) total number of unsaturated functional groups per 1000 carbon atoms: 0.8 or less, and

iv) R according to the following mathematical equation 1_vdThe value: 0.5 below:

[ mathematical equation 1]

(in mathematical equation 1, vinyl group, vinylene group and vinylene group represent the number of each functional group per 1000 carbon atoms as measured by nuclear magnetic spectrum analysis).

2. The ethylene/α -olefin copolymer according to claim 1, wherein the density is from 0.85g/cc to 0.89 g/cc.

3. The ethylene/α -olefin copolymer according to claim 1, wherein the weight average molecular weight may be from 17,000g/mol to 40,000 g/mol.

4. The ethylene/α -olefin copolymer according to claim 1, wherein the viscosity is from 8,500cP to 35,000cP when measured at a temperature of 180 ℃.

5. The ethylene/α -olefin copolymer of claim 1, wherein R is according to mathematical equation 1_vdThe value is 0.3 or less.

6. The ethylene/α -olefin copolymer according to claim 1, wherein the α -olefin comprises one or more selected from the group consisting of propylene, 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-heptene, 1-octene, 1-decene, 1-undecene, 1-dodecene, 1-tetradecene, 1-hexadecene, and 1-eicosene.

7. The ethylene/α -olefin copolymer according to claim 1, wherein the α -olefin is one or more selected from the group consisting of 1-butene, 1-hexene and 1-octene.

8. The ethylene/α -olefin copolymer according to claim 1, wherein the content of α -olefin is more than 0 to 99 mol% or less with respect to the total weight of the copolymer.

9. The ethylene/α -olefin copolymer according to claim 1, further satisfying the following conditions v) to vii):

v) total number of unsaturated functional groups per 1000 carbon atoms: the content of the organic acid is less than 0.8,

vi) number average molecular weight (Mn): 9,000 to 25,000, and

vii) Melt Index (MI) by ASTM D1238 at 190 ℃, 2.16kg load: 200dg/min to 1,300 dg/min.

Technical Field

Cross Reference to Related Applications

This application claims the benefit of korean patent application No. 2018-0052045, filed on 5/4 of 2018 to the korean intellectual property office, the contents of which are incorporated herein by reference.

Background

Olefin polymerization catalyst systems can be classified into ziegler-natta catalyst systems and metallocene catalyst systems, and have been developed according to the respective characteristics of the two high-activity catalyst systems. The ziegler-natta catalyst has been widely used in commercial processes since the invention in the 50 th century, but it is a multi-site catalyst in which many active sites coexist, and has a characteristic of wide molecular weight distribution of a polymer, and further, there is a limit in securing desired physical properties due to non-uniform composition distribution of a comonomer.

Meanwhile, the metallocene catalyst is composed of a combination of a main catalyst having a transition metal compound as a main component and a promoter which is an organometallic compound having aluminum as a main component, and the catalyst is a homogeneous complex catalyst and is a single-site catalyst. According to the single-site property, a polymer having a narrow molecular weight distribution and a uniform comonomer composition distribution is obtained, and spatial regularity, copolymerization property, molecular weight, crystallinity, etc. of the polymer may be changed according to structural deformation of a catalyst ligand and polymerization conditions.

U.S. Pat. No. 5,914,289 discloses a method of controlling molecular weight and molecular weight distribution of polymer using metallocene catalyst supported by each carrier, but the amount of solvent used for preparing the supported catalyst is consumed very much, the preparation time is long, and there is inconvenience in supporting the metallocene catalyst on each carrier.

Korean patent application No. 10-2003-0012308 discloses a method of controlling molecular weight distribution by supporting a dinuclear metallocene catalyst and a mononuclear metallocene catalyst together with an activator on a carrier and performing polymerization while changing the combination of the catalysts in a reactor. However, this method has limitations in simultaneously realizing properties of respective catalysts, and the metallocene catalyst is partially separated from the support component of the catalyst final product, thereby causing fouling in the reactor.

Meanwhile, linear low density polyethylene is prepared by copolymerizing ethylene and α -olefin using a polymerization catalyst at low pressure, and is a resin having a narrow molecular weight distribution and having short chain branches of a certain length without long chain branches. Linear low density polyethylene films have properties of common polyethylene, high breaking strength and elongation, and excellent tear strength and drop impact strength, and thus are increasingly used in stretch films, overlapped films, and the like, to which conventional low density polyethylene or high density polyethylene is difficult to apply.

However, most linear low density polyethylenes that use 1-butene or 1-hexene as the comonomer are produced in a single gas phase reactor or single loop slurry reactor and have higher productivity compared to processes that use 1-octene comonomers. However, due to the limitations of the catalyst technology used and the process technology used, the performance of this product is also much inferior to that of the case where 1-octene comonomer is used, and its molecular weight distribution is narrow, and therefore the processability is poor.

U.S. Pat. No. 4,935,474 reports a method for preparing polyethylene having a broad molecular weight distribution by using two or more metallocene compounds. U.S. Pat. No. 6,828,394 reports a method of preparing polyethylene having excellent processability and particularly suitable as a film by mixing a comonomer having good adhesion and a comonomer lacking these properties. In addition, U.S. Pat. No. 6,841,631 and U.S. Pat. No. 6,894,128 indicate that polyethylene having a bimodal or multimodal molecular weight distribution is prepared by using a metallocene catalyst in which at least two metal compounds are used, and the polyethylene is suitable for use in film, blow molding, pipe, and the like. However, although such products have improved processability, there is a problem in that, due to the non-uniform dispersion state of molecular weight in unit particles, the extrusion appearance is rough and the physical properties are unstable despite relatively good extrusion conditions.

In such a background, there is a continuous need to produce excellent products having a balance between physical properties and processability, and in particular, there is also a need for polyethylene copolymers having excellent physical properties (e.g., long-term properties).

Disclosure of Invention

Technical problem

Accordingly, the present invention has been made to solve the above-mentioned limitations of the conventional art, and provides an ethylene/α -olefin copolymer having a narrow molecular weight distribution, a small amount of unsaturated functional groups and R, and a method for preparing the same_vdA value showing excellent physical properties, particularly low after long-term storageViscosity change rate and excellent long-term physical properties, shows little high-temperature discoloration, and has excellent high-temperature stability.

In addition, the present invention provides a hot melt adhesive composition exhibiting excellent long-term properties, high-temperature stability and adhesive properties by including the ethylene/α -olefin copolymer.

Technical scheme

In order to accomplish the above task, according to one embodiment of the present invention, there is provided an ethylene/α -olefin copolymer satisfying the following conditions i) to iv):

i) viscosity: 6,000cP to 40,000cP if measured at a temperature of 180 ℃,

ii) Molecular Weight Distribution (MWD): 1.5 to 3.0, in a molar ratio,

iii) total number of unsaturated functional groups per 1000 carbon atoms: 0.8 or less, and

iv) R according to the following mathematical equation 1_vdThe value: 0.5 below:

[ mathematical equation 1]

(in mathematical equation 1, vinyl (vinyl), vinylene (vinylene), and vinylene (vinylene) represent the number of various functional groups per 1000 carbon atoms as measured by nuclear magnetic spectrum analysis).

Advantageous effects

The ethylene/alpha-olefin copolymer according to the present invention has a low density, an ultra-low molecular weight and a narrow molecular weight distribution, thereby exhibiting excellent impact strength and mechanical properties. In addition, the ethylene/α -olefin copolymer according to the present invention has a small total amount of unsaturated functional groups in the polymer, and a small ratio of vinylidene groups, and a small change rate of viscosity with time, exhibits excellent long-term properties, and exhibits little high-temperature discoloration, thereby exhibiting improved high-temperature stability.

Therefore, if the ethylene/α -olefin copolymer according to the present invention is applied to a hot melt adhesive composition, the fluidity or reactivity of the copolymer is relatively constant under various process conditions, and the reaction efficiency may be improved, and thus, a hot melt adhesive composition having excellent long-term properties, high temperature stability, and adhesiveness may be prepared.

Detailed Description

The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting of the invention. The singular is intended to include the plural unless the context clearly dictates otherwise. It will be understood that the terms "comprises" and/or "comprising," when used in this specification, specify the presence of stated features, steps, elements, or combinations thereof, but do not preclude the presence or addition of one or more other features, steps, elements, or combinations thereof.

While the invention is susceptible of various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and will herein be described in detail. It should be understood, however, that the invention is not to be limited to the particular forms disclosed, but to include all changes, equivalents, and alternatives falling within the scope and technical scope of the invention.

1. Ethylene/alpha-olefin copolymer

Hereinafter, the ethylene/α -olefin copolymer of the present invention will be explained in detail.

The ethylene/α -olefin copolymer according to an embodiment of the present invention satisfies the following conditions i) to iv):

i) viscosity: from 4,000cP to 50,000cP if measured at a temperature of 180 ℃,

ii) Molecular Weight Distribution (MWD): 1.5 to 3.0, in a molar ratio,

iii) total number of unsaturated functional groups per 1000 carbon atoms: 0.8 or less, and

iv) R according to the following mathematical equation 1_vdThe value: 0.5 below:

[ mathematical equation 1]

(in mathematical equation 1, vinyl group, vinylene group and vinylene group represent the number of various functional groups per 1000 carbon atoms as measured by nuclear magnetic spectrum analysis).

The crosslinking between the copolymers is performed by a vinyl group and a vinylidene group including a double bond, and in the ethylene/α -olefin copolymer according to an embodiment, the number of unsaturated functional groups in the copolymer may be reduced, particularly, the proportion of the vinylidene group may be reduced, particularly, the number of unsaturated functional groups and R_vdThe conditions can be satisfied by injecting an optimized amount of hydrogen together with the catalyst during polymerization (explained later), thereby exhibiting excellent high-temperature stability, i.e., reduced discoloration, molecular weight, and high-temperature viscosity change rate.

The ethylene/α -olefin copolymer according to the embodiment of the present invention, as described above, has a viscosity of 50,000cP or less if measured at 180 ℃, under the condition that the low density property is satisfied. More particularly, the ethylene/α -olefin copolymer may have a viscosity of 40,000cP or less, 37,000cP or less, or 35,000cP or less, and 4,000cP or more, or 6,000cP or more, or 7,000cP or more, or 8,500cP or more.

In particular, the ethylene/α -olefin copolymer according to one embodiment may have an unsaturated functional group number including a vinyl group, an ethyleneene group, and a vinylene group of 0.8 or less, more particularly 0.6 or less, or 0.5 or less, or 0.45 or less, or 0.40 or less, and 0.1 or more, or 0.2 or more, or 0.23 or more per 1000 carbon atoms in the copolymer.

In addition, R of the ethylene/α -olefin copolymer according to one embodiment is calculated according to mathematical equation 1_vdThe value may be 0.5 or less, more particularly 0.3 or less, or 0.25 or less, or 0.22 or less, and is greater than 0, or 0.1 or more, or 0.15 or more.

In the present invention, the amount (or number) of vinyl groups, vinylene groups and vinylidene groups which are unsaturated functional groups in the copolymer can be calculated from the results of NMR analysis. In particular, the copolymer was dissolved in chloroform-d (w/TMS) solution and measured at room temperature using an Agilent500MHz NMR instrument with a 2 second acquisition time, a 45 DEG pulse angle, 16 times. Then, TMS peak in 1H NMR was correctedWhen the concentration reached 0ppm, 0.88ppm of CH in 1-octene was observed₃Correlation peaks (triplet) and CH of ethylene at 1.26ppm₂Correlation peak (broad singlet), and converting CH₃The integral value of the peak was calibrated to 3 to calculate the content. In addition, each number can be calculated based on the integrated value of vinyl group, vinylene and vinylidene group in the region of 4.5-6.0 ppm.

In addition, in general, in the case of polymerizing two or more monomers, a Molecular Weight Distribution (MWD) is increased, and as a result, impact strength and mechanical properties may be reduced, and a blocking phenomenon or the like may occur. In this connection, in the present invention, an optimized amount of hydrogen may be injected during the polymerization reaction, the molecular weight and molecular weight distribution of the ethylene/α -olefin copolymer thus produced may be reduced, and as a result, impact strength, mechanical properties, and the like may be improved.

Further, the ethylene/α -olefin copolymer according to the embodiment of the present invention additionally has a density of 0.85g/cc to 0.89g/cc measured according to ASTM D-792 under the condition that the above-described physical property conditions are satisfied. In particular, the density may be 0.855g/cc or more, or 0.86g/cc or more, or 0.865g/cc or more, and 0.89g/cc or less, or 0.885g/cc or less, or 0.880g/cc or less.

In general, the density of an olefin-based polymer is affected by the kind and amount of monomers used during polymerization, the degree of polymerization, and the like, while a copolymer is greatly affected by the amount of comonomers. As the comonomer increases, an ethylene/α -olefin copolymer having a low density may be prepared, and the amount of comonomer that can be introduced into the copolymer may depend on the copolymerization properties of the catalyst, i.e., the properties of the catalyst.

In the present invention, since the catalyst composition including the transition metal compound having a specific structure is used, a large amount of comonomer can be introduced. As a result, the ethylene/α -olefin copolymer according to the embodiment of the present invention may have a low density as described above, and as a result, may exhibit excellent processability. More particularly, the ethylene/α -olefin copolymer may preferably have a density of 0.860g/cc to 0.885g/cc, more preferably 0.865g/cc to 0.880g/cc, and in this case, the effects of maintaining the mechanical properties and improving the impact strength are more significant according to the control of the density.

In addition, the ethylene/α -olefin copolymer according to an embodiment of the present invention has a Molecular Weight Distribution (MWD) of 1.5 to 3.0. In particular, the molecular weight distribution may be 2.5 or less, more particularly 1.7 or more, or 1.8 or more, or 1.9 or more, and 2.3 or less, or 2.1 or less, or 2.0 or less.

Meanwhile, in the present invention, the weight average molecular weight (Mw) and the number average molecular weight (Mn) are polystyrene-equivalent molecular weights analyzed by Gel Permeation Chromatography (GPC), and the molecular weight distribution can be calculated from the ratio of Mw/Mn.

The ethylene/α -olefin copolymer according to one embodiment of the present invention may be a polymer having an ultra-low molecular weight, which has a weight average molecular weight (Mw) of 15,000 to 45,000 g/mol. More particularly, the weight average molecular weight can be 17,000g/mol or more, or 19,000g/mol or more, and 40,000g/mol or less, or 37,000g/mol or less, or 35,000g/mol or less.

Further, the ethylene/alpha-olefin copolymer can have a Melt Index (MI) of from 200dg/min to 1300 dg/min. In particular, the melt index may be 400dg/min or more, 500dg/min or more, and 1200dg/min or less, 1000dg/min or less. The Melt Index (MI) is a value measured according to ASTM D-1238 (condition E, 190 ℃, 2.16kg load).

If the weight average molecular weight and the melt index satisfy the above ranges, it is suitable for application in a hot melt adhesive composition, and significant improvement in processability with respect to viscosity can be expected. That is, the viscosity affecting the mechanical properties and impact strength and processability of the ethylene/α -olefin copolymer can be controlled by controlling the kind of the catalyst used and the amount of the catalyst used during the polymerization, and by satisfying the viscosity range and the above conditions, improved processability can be exhibited while maintaining excellent mechanical properties.

In addition, the number average molecular weight (Mn) of the ethylene/α -olefin copolymer according to an embodiment of the present invention may be 5,000 to 35,000. More particularly, the number average molecular weight may be 7,000 or more, or 8,000 or more, or 9,000 or more, and 30,000 or less, or 25,000 or less.

In addition, the crystallization temperature (Tc) of the ethylene/α -olefin copolymer according to the embodiment of the present invention may be 45 ℃ or higher. More specifically, the crystallization temperature may be 50 ℃ or more, or 51 ℃ or more, and 60 ℃ or less, or 58 ℃ or less, or 56 ℃ or less. The high crystallization temperature as described above is caused by the uniform distribution of the comonomer in the ethylene/α -olefin copolymer, and in this temperature range, excellent structural stability can be exhibited.

In addition, the melting temperature (Tm) of the ethylene/α -olefin copolymer according to an embodiment of the present invention may be 60 ℃ to 80 ℃. More specifically, the melting temperature may be 65 ℃ or higher, or 69 ℃ or higher, or 70 ℃ or higher, and 75 ℃ or lower, or 74.5 ℃ or lower, or 74 ℃ or lower. At a melting temperature within the temperature range as described above, excellent thermal stability can be exhibited.

In the present invention, the crystallization temperature and the melting temperature of the ethylene/α -olefin copolymer can be measured using a Differential Scanning Calorimeter (DSC). In particular, the copolymer is heated to 150 ℃ for 5 minutes and cooled again to 20 ℃ and then the temperature is raised again. In this case, the rate of increase and the rate of decrease in temperature were controlled to 10 ℃/min, respectively, and the results measured in the portion where the temperature was increased for the second time were set as the melting temperature, and the results measured in the portion where the temperature was decreased were set as the crystallization temperature.

In addition, in the ethylene/α -olefin copolymer according to an embodiment of the present invention, the α -olefin-based monomer as a comonomer may be an olefin-based monomer having 4 to 20 carbon atoms. Specific examples may include propylene, 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-heptene, 1-octene, 1-decene, 1-undecene, 1-dodecene, 1-tetradecene, 1-hexadecene or 1-eicosene, and these monomers may be used alone or in a mixture of two or more.

Among them, in view of a significant improvement effect if applied to a hot melt adhesive composition, the α -olefin monomer may be 1-butene, 1-hexene or 1-octene, and most preferably, 1-octene may be used.

In addition, in the ethylene/α -olefin copolymer, the amount of the α -olefin as a comonomer may be appropriately selected from a range satisfying the above-described physical property conditions, and may be specifically more than 0 and 99 mol% or less, or 10 mol% to 50 mol%.

The ethylene/α -olefin copolymer according to another embodiment of the present invention satisfies the following conditions i) to vii):

i) viscosity: from 4,000cP to 50,000cP if measured at a temperature of 180 ℃,

ii) density: 0.85g/cc to 0.89g/cc,

iii) Molecular Weight Distribution (MWD): 1.5 to 3.0, in a molar ratio,

iv) total number of unsaturated functional groups per 1000 carbon atoms: the content of the organic acid is less than 0.8,

v) number average molecular weight (Mn): 9,000 to 25,000,

vi) Melt Index (MI) by ASTM D1238 at 190 ℃, 2.16kg load: 200dg/min to 1,300dg/min, and

vii) R according to mathematical formula 1_vdThe value: 0.5 below:

[ mathematical equation 1]

(in mathematical equation 1, vinyl group, vinylene group and vinylene group represent the number of various functional groups per 1000 carbon atoms as measured by nuclear magnetic spectrum analysis).

2. Process for preparing ethylene/alpha-olefin copolymer

Meanwhile, the ethylene/α -olefin copolymer having the above physical properties may be prepared by a preparation method comprising the steps of: ethylene and alpha-olefin-based monomers are polymerized by injecting hydrogen at 45cc/min to 100cc/min in the presence of a catalyst composition comprising a transition metal compound of the following formula 1. Accordingly, another aspect of the present invention provides a method for preparing an ethylene/α -olefin copolymer.

[ formula 1]

In the formula 1, the first and second groups,

R₁is hydrogen; alkyl of 1 to 20 carbon atoms; cycloalkyl of 3 to 20 carbon atoms; alkenyl of 2 to 20 carbon atoms; alkoxy of 1 to 20 carbon atoms; aryl of 6 to 20 carbon atoms; arylalkoxy of 7 to 20 carbon atoms; an alkylaryl group of 7 to 20 carbon atoms; or an aralkyl group of 7 to 20 carbon atoms,

R_2ato R_2eEach independently is hydrogen; halogen; alkyl of 1 to 20 carbon atoms; cycloalkyl of 3 to 20 carbon atoms; alkenyl of 2 to 20 carbon atoms; alkoxy of 1 to 20 carbon atoms; or an aryl group of 6 to 20 carbon atoms,

R₃is hydrogen; halogen; alkyl of 1 to 20 carbon atoms; cycloalkyl of 3 to 20 carbon atoms; alkenyl of 2 to 20 carbon atoms; aryl of 6 to 20 carbon atoms; an alkylaryl group of 6 to 20 carbon atoms; arylalkyl of 7 to 20 carbon atoms; an alkylamino group of 1 to 20 carbon atoms; arylamine groups of 6 to 20 carbon atoms; or a phenyl group substituted by one or more selected from the group consisting of halogen, alkyl of 1 to 20 carbon atoms, cycloalkyl of 3 to 20 carbon atoms, alkenyl of 2 to 20 carbon atoms, alkoxy of 1 to 20 carbon atoms and aryl of 6 to 20 carbon atoms,

R₄to R₉Each independently is hydrogen; a silyl group; alkyl of 1 to 20 carbon atoms; cycloalkyl of 3 to 20 carbon atoms; alkenyl of 2 to 20 carbon atoms; aryl of 6 to 20 carbon atoms; an alkylaryl group of 7 to 20 carbon atoms; arylalkyl of 7 to 20 carbon atoms; or a metalloid radical of a group 14 metal substituted with a hydrocarbyl group of 1 to 20 carbon atoms; wherein at R₆To R₉In the above-mentioned resin composition, two or more adjacent ones may be connected to each other to form a ring,

q is Si or C, and Q is Si or C,

m is a group 4 transition metal, and

X₁and X₂Each independently is hydrogen; halogen; alkyl of 1 to 20 carbon atoms;cycloalkyl of 3 to 20 carbon atoms; alkenyl of 2 to 20 carbon atoms; aryl of 6 to 20 carbon atoms; an alkylaryl group of 7 to 20 carbon atoms; arylalkyl of 7 to 20 carbon atoms; alkylamino of 1 to 20 carbon atoms; or arylamino of 6 to 20 carbon atoms.

As described above, in the case where the transition metal compound having the structure of formula 1 above is contained in the catalyst composition, and ethylene and the α -olefin-based comonomer are polymerized together with hydrogen, an ethylene/α -olefin copolymer having low density and ultra-low molecular weight can be prepared since the total number of unsaturated functional groups per 1,000 carbon atoms of the ethylene/α -olefin copolymer is 0.8 or less, and R is satisfied_vdThe value is 0.5 or less, and thus excellent high temperature stability including less discoloration at high temperatures, and small molecular weight and viscosity change rate can be exhibited.

That is, the crosslinking reaction that can be performed by the unsaturated functional group and the alkyl group in the copolymer is mainly performed in a vinyl group or a vinylidene group having relatively little steric hindrance among the unsaturated functional groups, and as the crosslinking reaction proceeds, the viscosity may greatly vary, the processability may be adversely affected, and as a result, the high temperature stability may be deteriorated. However, by applying the preparation method according to an embodiment of the present invention, the ratio of the vinylidene content among the unsaturated functional groups can be reduced, and thus the crosslinking reaction may not occur well, and finally, a copolymer having a small high temperature viscosity change rate can be realized.

The substituent in formula 1 will be explained more specifically as follows.

R₁May be hydrogen; alkyl of 1 to 20 carbon atoms; cycloalkyl of 3 to 20 carbon atoms; alkoxy of 1 to 20 carbon atoms; aryl of 6 to 20 carbon atoms; arylalkoxy of 7 to 20 carbon atoms; an alkylaryl group of 7 to 20 carbon atoms; or arylalkyl of 7 to 20 carbon atoms.

In particular, R₁May be hydrogen; alkyl of 1 to 12 carbon atoms; cycloalkyl of 3 to 12 carbon atoms; alkoxy of 1 to 12 carbon atoms; aryl of 6 to 12 carbon atoms; arylalkoxy of 7 to 13 carbon atoms; 7 toAn alkylaryl group of 13 carbon atoms; or arylalkyl of 7 to 13 carbon atoms.

More particularly, R₁And may be hydrogen or alkyl of 1 to 12 carbon atoms.

R_2aTo R_2eMay each independently be hydrogen; halogen; alkyl of 1 to 12 carbon atoms; cycloalkyl of 3 to 12 carbon atoms; alkenyl of 2 to 12 carbon atoms; alkoxy of 1 to 12 carbon atoms; or a phenyl group.

In particular, R_2aTo R_2eMay each independently be hydrogen; halogen; alkyl of 1 to 12 carbon atoms; cycloalkyl of 3 to 12 carbon atoms; alkenyl of 2 to 12 carbon atoms; alkoxy of 1 to 12 carbon atoms; or a phenyl group.

More particularly, R_2aTo R_2eMay each independently be hydrogen; alkyl of 1 to 12 carbon atoms; or alkoxy of 1 to 12 carbon atoms.

R₃May be hydrogen; halogen; alkyl of 1 to 12 carbon atoms; cycloalkyl of 3 to 12 carbon atoms; alkenyl of 2 to 12 carbon atoms; aryl of 6 to 20 carbon atoms; an alkylaryl group of 7 to 13 carbon atoms; arylalkyl of 7 to 13 carbon atoms; or phenyl substituted by one or more selected from halogen, alkyl of 1 to 12 carbon atoms, cycloalkyl of 3 to 12 carbon atoms, alkenyl of 2 to 12 carbon atoms, alkoxy of 1 to 12 carbon atoms and phenyl.

In particular, R₃May be hydrogen; halogen; alkyl of 1 to 12 carbon atoms; cycloalkyl of 3 to 12 carbon atoms; alkenyl of 2 to 12 carbon atoms; an alkylaryl group of 7 to 13 carbon atoms; arylalkyl of 7 to 13 carbon atoms; a phenyl group; or phenyl substituted by one or more selected from halogen, alkyl of 1 to 12 carbon atoms, cycloalkyl of 3 to 12 carbon atoms, alkenyl of 2 to 12 carbon atoms, alkoxy of 1 to 12 carbon atoms and phenyl.

More particularly, R₃May be hydrogen; alkyl of 1 to 12 carbon atoms; or a phenyl group.

R₄To R₉May each independently be hydrogen; alkyl of 1 to 20 carbon atoms; cycloalkyl of 3 to 20 carbon atoms; 6 to 20An aryl group of carbon atoms; an alkylaryl group of 7 to 20 carbon atoms; or arylalkyl of 7 to 20 carbon atoms.

In particular, R₄To R₉May each independently be hydrogen; alkyl of 1 to 12 carbon atoms; cycloalkyl of 3 to 12 carbon atoms; aryl of 6 to 12 carbon atoms; an alkylaryl group of 7 to 13 carbon atoms; or arylalkyl of 7 to 13 carbon atoms.

More particularly, R₄To R₅May each independently be hydrogen; or alkyl of 1 to 12 carbon atoms, and

at R₆To R₉Adjacent two or more may be connected to each other to form an aliphatic ring of 5 to 20 carbon atoms or an aromatic ring of 6 to 20 carbon atoms; the aliphatic or aromatic ring may be substituted with halogen, alkyl of 1 to 20 carbon atoms, alkenyl of 2 to 12 carbon atoms, or aryl of 6 to 12 carbon atoms.

In particular, in R₆To R₉Adjacent two or more may be connected to each other to form an aliphatic ring of 5 to 12 carbon atoms or an aromatic ring of 6 to 12 carbon atoms; the aliphatic or aromatic ring may be substituted with halogen, alkyl of 1 to 12 carbon atoms, alkenyl of 2 to 12 carbon atoms, or aryl of 6 to 12 carbon atoms.

More particularly, R₆To R₉May each independently be hydrogen or methyl.

In addition, Q may be Si, and M may be Ti.

X₁And X₂May each independently be hydrogen; halogen; alkyl of 1 to 12 carbon atoms; cycloalkyl of 3 to 12 carbon atoms; alkenyl of 2 to 12 carbon atoms; aryl of 6 to 12 carbon atoms; an alkylaryl group of 7 to 13 carbon atoms; arylalkyl of 7 to 13 carbon atoms; alkylamino of 1 to 13 carbon atoms; or arylamino of 6 to 12 carbon atoms.

In particular, X₁And X₂May each independently be hydrogen; halogen; alkyl of 1 to 12 carbon atoms; or alkenyl of 2 to 12 carbon atoms.

More particularly, X₁And X₂Can each beIndependently is hydrogen; or an alkyl group having 1 to 12 carbon atoms.

The transition metal compound of formula 1 forms the following structure: wherein cyclopentadiene is fused to benzothiophene via a cyclic bond, an amine group ((N-R)₁) Is stably cross-linked by Q (Si, C, N or P), and a group 4 transition metal forms a coordinate bond. If the catalyst composition is used for the polymerization of olefins, polyolefins having high activity, high molecular weight, and properties such as high degree of copolymerization at high polymerization temperature can be produced.

Further, in the transition metal compound of formula 1, due to the amine group (N-R)₁) Being cross-linked by Q (Si, C), since Q is bonded to a substituted or unsubstituted phenyl group, if a coordinate bond is formed with a transition metal, more stable cross-linking can be achieved, and electronically excellent stability can be achieved.

The transition metal compound having the above structure has excellent copolymerization properties due to the phenyl group, so that a copolymer having a low density can be prepared with a smaller amount of comonomer than a catalyst without a parent core structure similar to the transition metal compound of formula 1, and at the same time, has an advantage of stable hydrogen injection because the molecular weight is excellent and polymerization can be performed at a high temperature.

That is, in the present invention, the transition metal compound is used but an optimized amount of hydrogen is injected during the polymerization reaction, and thus, an ethylene/α -olefin copolymer having an ultra-low molecular weight, a narrow molecular weight distribution, and a uniform comonomer distribution can be provided. Hydrogen is advantageous due to the electronic/structural stability of the transition metal compound. Therefore, the termination reaction of the polymerization reaction proceeds uniformly due to hydrogen, and the effect that a copolymer having a narrow molecular weight distribution and an ultra-low molecular weight can be produced can be expected.

More specifically, specific examples of the compound of formula 1 may include compounds represented by any one of the following structures, but the present invention is not limited thereto.

Meanwhile, in the preparation of the ethylene/α -olefin copolymer according to an embodiment of the present invention, the catalyst composition may further include a promoter for activating the transition metal compound of formula 1 above.

The promoter is an organometallic compound containing a group 13 metal, and may specifically include one or more of a compound of the following formula 2, a compound of the following formula 3, and a compound of the following formula 4:

[ formula 2]

R₄₁-[Al(R₄₂)-O]_n-R₄₃

In the formula 2, the first and second groups,

R₄₁、R₄₂and R₄₃Each independently is any one of hydrogen, halogen, a hydrocarbon group of 1 to 20 carbon atoms, and a halogen-substituted hydrocarbon group of 1 to 20 carbon atoms, and

n is an integer of 2 or more,

[ formula 3]

D(R₄₄)₃

In formula 3, D is aluminum or boron, and

each R is₄₄Each independently any one of halogen, a hydrocarbon group of 1 to 20 carbon atoms and a halogen-substituted hydrocarbon group of 1 to 20 carbon atoms,

[ formula 4]

[L-H]⁺[Z(A)₄]^-Or [ L]⁺[Z(A)₄]^-

In the formula 4, the first and second organic solvents are,

l is a neutral or cationic Lewis acid; h is a hydrogen atom, and

z is an element of group 13, and each A is independently a hydrocarbon group of 1 to 20 carbon atoms; hydrocarbyloxy of 1 to 20 carbon atoms; any of substituents in which one or more hydrogen atoms are substituted with one or more substituents of halogen, hydrocarbyloxy of 1 to 20 carbon atoms, and hydrocarbylsilyl of 1 to 20 carbon atoms.

More particularly, the compound of formula 2 may be an alkylaluminoxane-based compound in which repeating units are combined into a linear, cyclic or network type, and specific examples may include Methylaluminoxane (MAO), ethylaluminoxane, isobutylaluminoxane or tert-butylaluminoxane.

In addition, specific examples of the compound of formula 3 may include trimethylaluminum, triethylaluminum, triisobutylaluminum, tripropylaluminum, tributylaluminum, dimethylaluminum chloride, triisopropylaluminum, tri-sec-butylaluminum, tricyclopentylaluminum, tripentylaluminum, triisopentylaluminum, trihexylaluminum, trioctylaluminum, ethyldimethylaluminum, methyldiethylaluminum, triphenylaluminum, tri-p-tolylaluminum, dimethylmethoxyaluminum, dimethylethoxyaluminum, trimethylboron, triethylboron, triisobutylboron, tripropylboron or tributylboron, and particularly, may be selected from trimethylaluminum, triethylaluminum or triisobutylaluminum.

In addition, the compound of formula 4 may include borate-based compounds based on a tri-substituted ammonium salt type, a dialkyl ammonium salt type, or a tri-substituted phosphonium salt type. More specific examples may include borate-based compounds of the tri-substituted ammonium salt type, such as trimethylammoniumtetraphenylborate, methyldioctadecylammonium tetraphenylborate, triethylammoniumtetraphenylborate, tripropylammoniumtetraphenylborate, tri (N-butyl) ammoniumtetraphenylborate, methyltetradecylactadecylammonium tetraphenylborate, N-dimethylaniliniumtetraphenylborate, N-diethylaniliniumtetraphenylborate, N-dimethyl (2,4, 6-trimethylanilinium) tetraphenylborate, trimethylammoniumtetrakis (pentafluorophenyl) borate, methyldiocetradecylammonium tetrakis (pentafluorophenyl) borate, methyldioctadecylammonium tetrakis (pentafluorophenyl) borate, triethylammoniumtetrakis (pentafluorophenyl) borate, tripropylammoniumtetrakis (pentafluorophenyl) borate, and mixtures thereof, Tri (N-butyl) ammonium tetrakis (pentafluorophenyl) borate, tri (sec-butyl) ammonium tetrakis (pentafluorophenyl) borate, N-dimethylanilinium tetrakis (pentafluorophenyl) borate, N-diethylanilinium tetrakis (pentafluorophenyl) borate, N-dimethyl (2,4, 6-trimethylanilinium) tetrakis (pentafluorophenyl) borate, trimethylammonium tetrakis (2,3,4, 6-tetrafluorophenyl) borate, triethylammonium tetrakis (2,3,4, 6-tetrafluorophenyl) borate, tripropylammonium tetrakis (2,3,4, 6-tetrafluorophenyl) borate, tri (N-butyl) ammonium tetrakis (2,3,4, 6-tetrafluorophenyl) borate, dimethyl (tert-butyl) ammonium tetrakis (2,3,4, 6-tetrafluorophenyl) borate, N-dimethylanilinium tetrakis (2,3,4, 6-tetrafluorophenyl) borate, N-diethylanilinium tetrakis (2,3,4, 6-tetrafluorophenyl) borate and N, N-dimethyl- (2,4, 6-trimethylanilinium) tetrakis- (2,3,4, 6-tetrafluorophenyl) borate; borate-based compounds of the dialkylammonium salt type, such as dioctadecylammoniumtetrakis (pentafluorophenyl) borate, ditetradecylammonium tetrakis (pentafluorophenyl) borate and dityclohexylammoniumtetrakis (pentafluorophenyl) borate; or borate-based compounds in the form of trisubstituted phosphonium salts, such as triphenylphosphonium tetrakis (pentafluorophenyl) borate, methyldioctadecylphosphonium tetrakis (pentafluorophenyl) borate and tris (2, 6-dimethylphenyl) phosphonium tetrakis (pentafluorophenyl) borate.

By using such an accelerator, the molecular weight distribution of the finally produced ethylene/α -olefin copolymer can be made more uniform, and the polymerization activity can be improved.

An appropriate amount of the accelerator may be used so that the transition metal compound of formula 1 may be sufficiently activated.

Further, the catalyst composition may include the transition metal compound of formula 1 in a supported state on a carrier.

If the transition metal compound of formula 1 is supported on a carrier, the weight ratio of the transition metal compound to the carrier may be 1:10 to 1:1,000, more preferably 1:10 to 1: 500. If the support and the transition metal compound are contained in this weight ratio range, an optimum shape can be exhibited. In addition, if the promoters are supported together on the carrier, the weight ratio of the promoters to the carrier may be 1:1 to 1:100, more preferably 1:1 to 1: 50. If the promoter and the support are contained in this weight ratio, the catalyst activity can be improved, and the microstructure of the polymer thus produced can be optimized.

Meanwhile, the support may use silica, alumina, magnesia or a mixture thereof, or may contain hydroxyl groups having high reactivity after removing moisture from the surface by high-temperature dryingOr a state of siloxane groups. In addition, the support dried at high temperature may further include an oxide, carbonate, sulfate, or nitrate component, such as Na₂O、K₂CO₃、BaSO₄And Mg (NO)₃)₂。

The drying temperature of the support is preferably 200 ℃ to 800 ℃, more preferably 300 ℃ to 600 ℃, and most preferably 300 ℃ to 400 ℃. If the drying temperature of the support is less than 200 ℃, the humidity is too high and water on the surface may react with the accelerator, and if the temperature is more than 800 ℃, pores on the surface of the support may be combined, so that the surface area is reduced, and a large amount of hydroxyl groups on the surface may be removed while leaving only siloxane groups, undesirably reducing the reaction sites with the accelerator.

Further, the amount of hydroxyl groups on the surface of the support may preferably be 0.1 to 10mmol/g, and more preferably 0.5 to 5 mmol/g. The amount of hydroxyl groups on the surface of the support can be controlled by the method and conditions for preparing the support, or the drying conditions (such as temperature, time, vacuum, and spray drying).

Meanwhile, the polymerization reaction of the ethylene/α -olefin copolymer may be performed by continuously injecting hydrogen in the presence of the catalyst composition and continuously polymerizing ethylene and the α -olefin-based monomer.

In this case, the hydrogen gas suppresses a rapid reaction of the transition metal compound at the initial stage of polymerization and acts to terminate the polymerization reaction. Therefore, by using such hydrogen and controlling the amount thereof used, an ethylene/α -olefin copolymer having a narrow molecular weight distribution and an ultra-low molecular weight can be efficiently produced.

Hydrogen can be injected at 45cc/min to 100cc/min, more specifically 50cc/min to 95 cc/min. If hydrogen is injected under the above conditions, the ethylene/α -olefin polymer thus produced can achieve the physical properties in the present invention. If hydrogen is injected in an amount of less than 45cc/min, termination of the polymerization reaction may not be uniformly performed and it may become difficult to prepare the ethylene/α -olefin copolymer having desired physical properties, and if the amount is more than 100cc/min, the termination reaction may occur too quickly, and it is understood that an ethylene/α -olefin copolymer having an excessively small molecular weight may be prepared.

Further, the polymerization reaction may be carried out at 80 to 200 ℃, but the number of unsaturated functional groups in the ethylene/α -olefin copolymer can be more advantageously controlled by controlling the injection amount of hydrogen and the polymerization temperature. Thus, in particular, the polymerization reaction can be carried out at from 100 ℃ to 150 ℃, more particularly at from 100 ℃ to 140 ℃.

In addition, during the polymerization reaction, an organoaluminum compound is further injected to remove moisture in the reactor, and the polymerization reaction may be carried out in the presence of the compound. Specific examples of such organoaluminum compounds may include trialkylaluminums, dialkylaluminum halides, alkylaluminum dihalides, dialkylaluminum hydrides or alkylaluminum sesquihalides, etc., and more specific examples may include Al (C)₂H₅)₃、Al(C₂H₅)₂H、Al(C₃H₇)₃、Al(C₃H₇)₂H、Al(i-C₄H₉)₂H、Al(C₈H₁₇)₃、Al(C₁₂H₂₅)₃、Al(C₂H₅)(C₁₂H₂₅)₂、Al(i-C₄H₉)(C₁₂H₂₅)₂、Al(i-C₄H₉)₂H、Al(i-C₄H₉)₃、(C₂H₅)₂AlCl、(i-C₃H₉)₂AlCl or (C)₂H₅)₃Al₂Cl₃. Such an organoaluminum compound may be continuously injected into the reactor, and in order to suitably remove moisture, the organoaluminum compound may be injected in a proportion of about 0.1 to 10 moles per 1kg of the reaction medium injected into the reactor.

Further, the polymerization pressure may be about 1Kgf/cm²To about 100Kgf/cm²Preferably about 1Kgf/cm²To about 50Kgf/cm²More preferably about 5Kgf/cm²To about 30Kgf/cm²。

In addition, if the transition metal compound is used in a state of being supported on a carrier, it may be injected after dissolving or diluting the transition metal compound in an aliphatic hydrocarbon solvent of 5 to 12 carbon atoms (e.g., pentane, hexane, heptane, nonane, decane and isomers thereof), an aromatic hydrocarbon solvent (e.g., toluene and benzene), a hydrocarbon solvent substituted with a chlorine atom (e.g., dichloromethane and chlorobenzene), or the like. The solvent used herein is preferably used after treatment with a small amount of aluminum alkyl to remove a small amount of water or air that can act as a catalyst poison, and a promoter may be further used.

The ethylene/α -olefin copolymer prepared by the above preparation method has a narrow molecular weight distribution and an ultra-low molecular weight and, at the same time, the vinyl content in the polymer can be minimized, and R_vdThe condition of 0.5 or less is satisfied. Therefore, excellent physical properties, particularly excellent stability at high temperature, may be exhibited, and if it is applied to a hot melt adhesive composition, processability as well as adhesive properties may be improved.

Thus, according to another embodiment of the present invention, there is provided a hot melt adhesive composition comprising the ethylene/a-olefin copolymer.

The hot melt adhesive composition may be prepared and used according to a conventional method, except that it contains the above-mentioned ethylene/α -olefin copolymer as a main component.